function xpcom_sca = NAO_pcom_sca(x,  p, a)
xpcom_sca = (-143319*cos(x(1) + x(2)))/342736250 -  ...
 (143319*cos(x(1) + x(2) + x(3) - x(4)))/342736250 -  ...
 (183515043716839333*sin(x(1)))/2229113584019525000 -  ...
 (115136616550093*sin(x(1) + x(2)))/1555109247328165 -  ...
 (3951410064115*sin(x(1) + x(2) + x(3)))/57532298899051 +  ...
 (9299254606247*sin(x(1) + x(2) + x(3) - x(4)))/622043698931266 +  ...
 (40565144278032223*sin(x(1) + x(2) + x(3) - x(4) - x(5)))/4458227168039050000 ...
;